Condensation preventing means for refrigerators



June 15, 1948. v 2,443,342

CONDENSATION PREVENTING MEANS FOR REFRIGERATORS Filed Feb. -l2. 1947 /3I 5 l3 l4 mvawox. DONALD Couaw A TTORNEY Patented June 15, 1948CONDENSATION PREVENTING MEANS FOR REFRIGERATORS Donald Colvin, SanFrancisco, Calif.

Application February 12, 1947, Serial No. 728.088

Claims. (CI. 82-89) The present invention relates to improvements incondensation preventing means for refrigerators, and has particularreference to reach-in frozen food cabinets used principally in storesfor storing and exhibiting to customers packaged frozen foods. Moreparticularly my invention has reference to cabinets of the characterdescribed which have swinging doors in the front wall thereof, the doorsbeing provided with transparent panels to allow the customer to inspectthe goods displayed and to open the doors for removing selectedpackages, the cabinet being provided with a plurality of shelvesrendering the individual packages more easily accessible.

One of the most attractive features of a frozen food cabinet of thischaracter, as compared with the conventional cabinets equipped withsliding doors in the top surface, is the facility with which thepackages may be examined from the outside without opening the doors, andthe ease with which they may be selected and removed by the customer.

The temperature in these cabinets is usually kept around zero, and Ihave found that due to the great difference in temperature between theinside of the cabinet and the outside atmosphere, when the door isopened the moisture of the outside air will rapidly condense on theinner surface of the glass or other transparent material used in a doorand that when the door is closed again this moisture will freeze on theglass and thus render the latter non-transparent, which defeats one ofthe main purposes of using glass doors.

It is the object of the present invention to overcome this dimculty andto provide means whereby the condensed moisture is carried away from theinside of the glass panel immediately upon the closing of the door andbefore it has had time to freeze on the panel and to form a nontransparent layer of frost thereon.-

For this purpose it is proposed to provide localized means for heatingthe front portion of the cabinet adjacent the door or doorsand to causea draft of heated air to rise along the inner face of the door forcarrying away the moisture and depositing it at a point where theformation of frost does no harm.

It is further proposed to arrange the heating means in such a mannerthat it does not interfere with the handling of the packages and remainsunaffected by the opening and closing of the door.

It is a further object of the invention to provide means whereby theheat draft is distributed over the glass panel area with substantialuniformity so as to substantially clear the entire area of the moisturewhen the door is closed.

And finally, it is proposed to utilize a heating means which at the sametime serves to illuininate the entire cabinet and to thus display thepackages to better advantage for inspection from the outside of thecabinet. I

Further objects and advantages of my invention will appear as thespecification proceeds, and the novel features of my invention will befully defined in the claims attached hereto.

The preferred form of my invention .is illustrated in the accompanyingdrawing, in which Figure 1 shows a front view of my cabinet; Figure 2. avertical section taken along line 2--2 of Figure 1; and

tion.

Referring to the drawings in detail. my cabinet I is preferably maderectangular in form and of substantial height, the cabinet including arear wall 2, side walls 3, a front wall 4 and a 'top 5, all made ofconventional construction and being heavily insulated, as shown.

The lower portion of the cabinet generally indi-' cated at i isreserved, in a conventional manner, for refrigerating apparatus, notshown. Above the refrigerating compartment is disposed an insulatedhorizontal wall I forming the bottom of the storage compartmentindicated at I.

The latter is provided with a plurality of conventional shelves Iarranged in vertically spaced relation and supported on suitable angleirons ll running along the side walls of the compartment.

The shelves have evaporator coils ll imbeddd at' I4 and adapted to belocked in closed position by suitable latches i5.

Each of the mullions has a.plurality of electrical light bulbs l6mounted on the inner facethereof, the light bulbs being preferablyarranged in fairly close proximity to the front wall and beingpreferably distributed so that one bulb is provided on each mullion foreach space between two shelves. The light bulbs should preferably bepositioned sufficiently high with respect to the shelves next below sothat the packages on each shelf clear the light bulb and may be movedback and forth without striking the latter. Similarly positioned lightbulbs are preferably mounted on the side walls, as shown.

Each door is formed with a, number of spaced glass panels ll, extendingpreferably through the major portion of the door.

It will be noted, particularly upon inspection of Figures 2 and 3, thatthe shelves 9 are constructed to stop short of the front and rear wallsof the cabinet.

In operation, with the light bulbs lit, the front portion of the cabinetwill be heated. When the door is opened and moisture settles on theinner face of the glass panel, and the door is then closed again, heatedair will rise along said inner face and will immediately entrain andremove the moisture before it can freeze on the glass panel. Themoisture is carried away and deposited in some other part of the cabinetwhere it does not interfere with visibility. In the use of my cabinet Ifind that a certain amount of excess frost collects on the front edgesof the shelves, and it may be assumed that most of the moisture isdeposited on the front edges of the shelves.

Particular attention is called to the fact that the shelves. beingslightly spaced from the front wall, serve to form a draft passage forthe heated air and at the same time serve to spread the rising air intoa relatively narrow passage for uniform disposition over the entirepanel area. It should also be noted that due to this construction theheated draft is substantially confined to the area immediately adjacentthe doors. and that little heat spreads into the interior of thecabinet.

Since the rear edges of the shelves are spaced from the rear wall, areturn draft passage is set up along the latter.

While the bulbs thus serve to keep the glass panels clear of frost theyserve the further purpose of illuminating the inside of the cabinet andto allow the entire contents of the cabinet to be easily surveyed fromthe outside.

It stands to reason that a somewhat increase freezing capacity is neededto make up for the heating but this feature is clearly outweighed b theadvantages gained.

I claim:

1. A frozen food cabinet having a front wall with a transparent door.therein adapted to collect moisture on the inner face thereof when open,shelves mounted in the cabinet, and heating means mounted within thecabinet adjacent the door to set up an upward draft along the inside ofthe closed door for entraining the moisture and for preventing theformation of frost upon the inner face of the door. the front edges ofthe shelves being slightly spaced from the closed door to present narrowdraft passages tending to spread the draft over the entire door area.

2. A frozen food cabinet having a rear wall. a front wall with atransparent door therein adapted to collect moisture on the inner facethereof when open, shelves mounted in the cabinet, and heating meansmounted within the cablalong the inside of the closed door forentraining the moisture and for preventing the formation of frost uponthe inner face of the door, the front edges of the shelves beingslightly spaced from the closed door to present narrow draft passagestending to spread the draft over the entire door area, and the rear,edges of the shelves being slightly spaced from the rear wall to providea return draft passage.

3. A frozen food cabinet having a front wall with a transparent doortherein adapted to collect moisture on the inner face thereof when open,shelves mounted in the cabinet-and heating means mounted within thecabinet adjacent the door to set up an upward draft along the inside ofthe closed door for entraining the moisture and for preventing theformation of frost upon the inner face of the door, the-front edges ofthe shelves'being slightly spaced from the closed door to present narrowdraft passages tending to spread the draft over the entire door area.the heating means being operative to illuminate the inside of thecabinet for display purposes.

4. A frozen food cabinet having a rear wall, a frontwall with atransparent door therein adapted to collect moisture on the inner facethereof when open, shelves mounted in the cabinet, and heating meansmounted within the cabinet adiacent the door to set up an upward draftalong the inside of the closed door for entraining the moisture and forpreventing the formation of frost upon the inner face of the door, thefront edges of the shelves being slightly spaced from the closed door topresent narrow draft passages tendingto spread the draft over the entiredoor area, and the rear edges of the shelves being slightly spaced fromthe rear wall to provide a return draft passage, the heating means beingoperative to illuminate the inside of the cabinet for display purposes.

5. A frozen food cabinet having a front wall with a transparent doortherein adapted to collect moisture on the inner face thereof, whenopen, shelves mounted in the cabinet, and heating means mounted withinthe cabinet adjacent the door to set up an upward draft along the insideof the closed door for entraining the moisture and for preventing theformation of frost upon the inner. face of the door, the front edges ofthe shelves being slightly spaced from-the closed door to present narrowdraft passages tending to spread the draft over the entire door area,the heating means comprising electrical light bulbs mounted on oppositesides of the door and between the shelves so as to clear the dooropenings.

DONALD COLVIN.

- REFERENCES crran The following references are of record in the file ofthis patent:

' UNITED STATES PATENTS Number Name Date 1,285,114 Gamache Nov. 19, 19181,757,718 Kauffmann May 6, 1930 2,172,284 Lieberman Sept. 5, 1939

